1. Technical Field
The present invention relates to an intermediate transfer material used for an image forming method of developing an electrostatic latent image on an electrostatic latent image carrier utilizing a liquid toner. The image, which is visualized by the development, is electrostatically transferred onto an intermediate transfer material, and the re-transferring from the intermediate transfer material onto final transfer objects, for example, an intermediate transfer material used for the image forming method adopted in copiers and laser beam printers.
2. Background Techniques
The intermediate transfer materials used for the above image forming method include the following.
For example, EP Laid-Open No. 399186 (Conventional Example 1) discloses an intermediate transfer material with a two-layer elastic layer consisting of a thin dielectric layer smooth on the surface and a conductive layer supporting the dielectric layer, and as for the material of the dielectric layer, it is only stated to simply use silicone coating or fluorine coating, etc.
Japanese Patent Laid-Open (Kokai) No. 3-243973 (Conventional Example 2) discloses an intermediate transfer material with an elastic layer smooth on the surface and capable of absorbing the solvent in the liquid toner. The elastic layer consists of a dielectric layer and a conductive layer. An example of the intermediate material has a conductive silicone rubber coated with an insulating silicone rubber.
Furthermore, U.S. Pat. No. 5,099,286 (Conventional Example 3) discloses an intermediate transfer material with a dielectric layer formed on a conductive base. An example of the intermediate transfer material has a dielectric layer made of polytetrafluoroethylene layer formed on a conductive base made of urethane rubber.
The intermediate transfer materials used for the above mentioned image forming method are required to satisfy the following requirements.
(1) The visible image should be able to be efficiently transferred onto the intermediate transfer material. PA1 (2) The visible image on the intermediate transfer material should be able to be efficiently re-transferred onto final transfer objects. PA1 (3) The intermediate transfer material should be durable.
However, the above Conventional Examples 1 to 3 do not satisfy all of the requirements (1) to (3).
For example, if a material like silicone coating or fluorine coating is simply used as in Conventional Example 1, the durability is not sufficient. In Conventional Example 2, since a conductive silicone rubber is used for the elastic layer, the solvent used in the liquid toner swells the elastic layer, to disturb the visible image on the intermediate transfer material. Furthermore in Comparative Example 3, since polyurethane rubber is used for the elastic layer, re-transferring onto the final transfer objects by a heat roller cannot be effected since polyurethane rubber is insufficient in heat resistance.